A flexible display device according to an embodiment includes a flexible plate including a display area, a non-display area surrounding the display area, an edge bending area near the display area in the non-display area and a pad area extending from the edge bending area; a first thin film transistor in the display area on the flexible plate; a first line disposed in the edge bending area on the flexible plate; a first buffer layer covering the first line; a second line on the first buffer layer in the edge bending area; a second buffer layer covering the second line; a connecting electrode is electrically connected the first line and the second line in the edge bending area; and a plurality of trenches disposed at the edge bending area and penetrating the second buffer layer and the first buffer layer.